A need exists to develop better commercial devices and methods to accelerate various reactions including, for example, heterogeneous reactions, oxidation-reduction reactions, and heterogeneous electron transfer reactions. Such improvements would be useful in many electrochemical devices and processes including, for example, operation of fuel cells and batteries, as well as various synthesis and production processes. Also, a need exists to reduce the use of expensive precious metal catalysts and electrodes.
Sonochemistry and use of ultrasound to impact chemical reactions are known fields. See, for example, T. J. Mason, Sonochemistry: The Uses of Ultrasound in Chemistry, The Royal Society of Chemistry (1990). Sonochemistry equipment, including ultrasound horns, is described in Lindley et al., Chem. Soc. Rev. 1987, 16, 275-311.
While ultrasonic methods have been used in conjunction with electrochemical systems to create sonoelectrochemical systems, the results have often been difficult to interpret, and commercialization of the sonoelectrochemical devices and processes have been limited despite interest. See Gonzalez-Garcia et al., Ultrasonics, 50, 2010, 318-322. Ultrasound technology could be useful for both electroanalytic and electrosynthetic processes. In many cases, use of high power ultrasound is stressed. Sonoelectrochemical cells have been described. For example, a 500 kHz sonoelectrochemical cell is described in Del Campo et al., Ultrasonics Sonochemistry 6 (1999) 189-197 (FIG. 1). See also, generally, US Pat. Pubs. 2005/0139484; 2008/0283411; 2008/0028858; 2012/0058405; 2013/0048506; and 2014/0158550.